Compression hold-down elements

ABSTRACT

Workpiece hold-down elements for holding the workpiece between the jaws of a machine vise, said jaws being shaped to prevent the hold-down elements from slipping. The hold-down elements are of channel shape with top and bottom portions thereof connected by a web that is slightly curved. These top and bottom portions are engaged by a face of the vise jaw so that when pressure is exerted on the elements by the vise the work engaging front of each element is pressed against the workpiece. The face of each jaw is provided with a groove for receiving the rear portion of each of the top parts of the hold-down elements to prevent these from slipping with respect to the vise jaws. Accidental displacing the hold-down elements with respect to the workpiece is prevented. The top parts of the hold-down elements are also provided with hardened steel or other metal shoes. The forward parts of the hardened shoes engage the workpiece and these are sufficiently hard to resist wear. The bodies of the elements may be made of softer material such as extruded aluminum or alloys thereof.

United States Patent 1 1 Clugage 1 1 COMPRESSION HOLD-DOWN ELEMENTSRobert G. Clugage, P.O. Box 5021, Incline Village, Nev. 89450 [76]Inventor:

[ Notice: The portion of the term of this patent subsequent to Feb. 12.1991. has been disclaimed.

[22] Filed: Jan. 16, 1974 211 App]. No.: 433,898

Related US. Application Data [63] Continuation-impart of Scr. No.273.971, July 21,

1972, Pat. N0. 3.791.640.

Primary Examiner-Roy Lake Assistant Examiner-Mark S. Bicks Attorney,Agent, or Firm-Ben .l. Chromy; Gerald L.

Moore 1*June 24, 1975 5 7 ABSTRACT Workpiece hold-down elements forholding the workpiece between the jaws of a machine vise, said jawsbeing shaped to prevent the hold-down elements from slipping. Thehold-down elements are of channel shape with top and bottom portionsthereof connected by a web that is slightly curved. These top and bottomportions are engaged by a face of the vise jaw so that when pressure isexerted on the elements by the vise the work engaging front of eachelement is pressed against the workpiece. The face of each jaw isprovided with a groove for receiving the rear portion of each of the topparts of the hold-down elements to prevent these from slipping withrespect to the vise jaws. Accidental displacing the hold-down elementswith respect to the workpiece is prevented. The top parts of thehold-down elements are also provided with hardened steel or other metalshoes. The forward parts of the hardened shoes engage the workpiece andthese are sufficiently hard to resist wear. The bodies of the elementsmay be made of softer material such as extruded aluminum or alloysthereof.

2 Claims, 3 Drawing Figures COMPRESSION HOLD-DOWN ELEMENTS DESCRIPTIONOF THE INVENTION This application is a continuation-in-part of myApplication Ser. No. 273,971 filed July 21, 1972 now US. Pat. No.3,791,640.

This invention relates to compression hold-down cle ments for use withmachine vise jaws shaped to prevent accidental displacement of thehold-down elements when pressure is applied thereto during the grippingof a workpiece therebetween.

An object of this invention is to provide an improved combination ofhold-down elements and machine vise for holding a workpiece firmlytherebetween.

Another object of this invention is to provide improved workpiecehold-down elements which may be made of extruded aluminum or aluminumalloys and which are provided with hardened workpiece-engaging membersor shoes.

Another object of this invention is to provide an improved arrangementof workpiece hold-down elements and machine vise jaws provided withrecesses to prevent the hold-down elements from accidentally slipping orbeing dislodged when pressure is applied to the elements by the vise.Said elements are of channel shape and each of them is provided with aweb between the vise engaging top portion and lower portion thereof.Said web is adapted to flex slightly so that the holddown elements pressthe workpiece downward firmly. The faces of the jaws of the vise aregrooved or recessed to receive a rear part of each of the hold-downelements so that the elements can not be accidentally dislodged from thefaces of the jaws when pressure is applied thereto.

Other and further objects of this invention will be apparent to thoseskilled in the art to which it relates from the following specification,claims and drawing.

In accordance with this invention I have provided an improvedarrangement for holding a workpiece in a machine vise so that theworkpiece will be held with precision during milling. grinding or otheroperations being performed thereon. In this invention the workpiece ispositioned between a pair of hold-down elements, each of which is of achannel shape and each of which is also provided with a top portion anda bottom portion which are connected by a web of arcuate shape. The topportion of each hold-down element is provided with a hardenedwork-engaging shoe which extends between the workpiece and the jaw ofthe vise. Providing the hold'down element with such a hardened shoepermits making the balance of the hold-down element of softer materialsuch as aluminum or aluminum alloys by the extrusion process. Thehardened shoe is attached to the hold-down element by means of rivets,screws or the like. The rounded front portion of the hardened shoeextends forward of the body of the element so that it engages theworkpiece. The angular rear part of the hardened shoe or member extendsinto a horizontal groove or recess provided to the vise jaw so that whenpressure is applied to the element by the vise the element can notaccidentally slip or become dislodged from the vise. Thus, the hold-downelements can not accidentally release the workpiece or allow theworkpiece to shift during the grinding, milling or other operationsbeing performed thereon.

Further details and features of this invention will be set forth in thefollowing specification, claims and drawing in which briefly:

FIG. I is a view in side elevation showing the holddown elements andvise arrangement of this invention holding a workpiece;

FIG. 2 is a perspective view of the arrangement shown in FIG. 1; and

FIG. 3 is an end view of one of the hold-down elements.

Referring to the drawing in detail, reference numeral 10 designates aflat plate which may be the base of a conventional vise or it may be thetable of a metal working machine such as a milling machine. Base 10 isprovided with a stationary jaw 11 and an adjustable jaw 12. The metalworkpiece l3 and the hold-down elements 14 and 15 are held firmlybetween the jaws 11 and 12. Thus, opposite sides of the workpiece 13 areengaged by the hold-down elements 14 and 15, respectively.

Hold-down element 14 is provided with a shoe or member 14a of hardenedsteel or the like which is firmly attached to the top portion 14b byseveral rivets 140. The rounded forward part of the shoe 14a engages aside of the workpiece 13 while the angular rear part of this shoeengages the vise jaw 11 in the upper part of the recess 11a which isprovided to the face of the vise jaw and extends horizontally acrossthis face. The lower part 14d of the hold-down element 14 is providedwith a rear flat face that engages the front face of the jaw 11. Theforward part of the member 1411 is connected to the upper part 1417 bythe web which is adapted to flex slightly when the workpiece 13 isclamped.

Hold-down element 15 is the same as hold down element l4 and it isprovided with a shoe 15a of hardened steel that is attached to the upperpart 15b by several rivets 15:- so that the parts 15a and 15b are firmlyat tached to each other. The hardened shoe 15a is provided with arounded front that engages the workpiece 13. The angular rear part ofthe shoe engages the jaw 12 of the vise in the recess 12a which extendshorizontally across the face of the jaw. The bottom part 15a of thehold-down element is provided with a flat rear surface that engages thelower part of the vise jaw. Part 15d is attached to the upper part 15bby the web l5e which is adapted to flex slightly when the workpiece 15is clamped. The parts 15b, 15d and l5e of hold-down element 15 are madeof extruded aluminum or alloys thereof the same as corresponding partsof the holddown element 14.

The workpiece 13 is supported by the parallel members 16 and 17. Thuswhen pressure is applied to holddown elements 14 and 15 by the jaws 11and 12 of the vise, the hardened members 14a and 15a of the holddown 14and 15, respectively, apply downward pressure on the workpiece l3pressing this workpiece firmly against the parallel supports 16 and 17.This downward pressure results from the fact that the hardened members14a and 15a are tilted at slight angles D with respect to the horizontaland the pressure of the vise on the hold-down elements tends to increasethis angle. Thus there is a tendency for the angular rear parts of thehardened members 14a and 15a to slip with respect to the vise jaws 11and 12, respectively. However. this tendency to slip is prevented by therecesses lla and 12a provided in the jaws 11 and 12, respectively. Theserecesses therefore prevent the accidental slippage and release of thehold-down elements. Also providing the recesses 11a and 12a to the visejaws re duces the likelihood of the webs 14c and 150 of the hold-downelements being deformed if these webs are made'of extruded aluminum andif considerable pres sure is applied to the hold-down elements by thevise. The hardened members 14a and 15a form the parts of the hold-downelements receiving the greatest wear and since these members are ofhardened steel the life of the hold-down elements is greatly prolonged.

While I have shown and described a preferred form of the invention itwill be apparent that the invention is capable of variation andmodification from the form shown so that the scope thereof should belimited only by the proper scope of the claims appended thereto.

What i claim is:

l. A compression hold-down and clamping device for holding a work-piecedown upon supporting means interposed between the jaws of the clampingdevice, the combination comprising a hold-down element having anelongated top member, said top member having a rounded forward surfacefor engaging the workpiece, an elongated bottom member the forward partsof said members being joined by a web. a clamping device comprising apair of jaws and means to move one jaw toward the other to effect aclamping action. the jaws of the clamping device each having ahorizontally extending recess for receiving the rear part of said topmember to prevent said top member from slipping when pressure is appliedthereto, said bottom member engaging said jaw of the clamping devicenear the bottom of said jaw, said top member being tilted at apredetermined angle with respect to the side of the workpiece engagedthereby. said predetermined angle is slightly reduced when pressure isapplied to said top member and said rear parts of said top member andsaid bottom member are moved away from each other as said web if flexedwhereby the workpiece is pressed down on the supporting means.

2. A compression hold-down and clamping device as set forth in claim 1,further characterized in that said top member comprises two parts, meansfastening said two parts together so that one of said parts is on top ofthe other, said top part being of hardened metal and being provided withsaid rounded forward surface for engaging said workpiece and the rearend of said top part engaging said jaw in said recess.

1. A compression hold-down and clamping device for holding a work-piecedown upon supporting means interposed between the jaws of the clampingdevice, the combination comprising a hold-down element having anelongated top member, said top member having a rounded forward surfacefor engaging the workpiece, an elongated bottom member, the forwardparts of said members being joined by a web, a clamping devicecomprising a pair of jaws and means to move one jaw toward the other toeffect a clamping action, the jaws of the clamping device each having ahorizontally extending recess for receiving the rear part of said topmember to prevent said top member from slipping when pressure is appliedthereto, said bottom member engaging said jaw of the clamping devicenear the bottom of said jaw, said top member being tilted at apredetermined angle with respect to the side of the workpiece engagedthereby, said predetermined angle is slightly reduced when pressure isapplied to said top member and said rear parts of said top member andsaid bottom member are moved away from each other as said web is flexedwhereby the workpipece is pressed down on the supporting means.
 2. Acompression hold-down and clamping device as set forth in claim 1,further characterized in that said top member comprises two parts, meansfastening said two parts together so that one of said parts is on top ofthe other, said top part being of hardened metal and being provided withsaid rounded forward surface for engaging said workpiece and the rearend of said top part engaging said jaw in said recess.